icuSources/common/mutex.h

   1 // © 2016 and later: Unicode, Inc. and others.
   2 // License & terms of use: http://www.unicode.org/copyright.html
   3 /*
   4 ******************************************************************************
   5 *
   6 *   Copyright (C) 1997-2013, International Business Machines
   7 *   Corporation and others.  All Rights Reserved.
   8 *
   9 ******************************************************************************
  10 */
  11 //----------------------------------------------------------------------------
  12 // File:     mutex.h
  13 //
  14 // Lightweight C++ wrapper for umtx_ C mutex functions
  15 //
  16 // Author:   Alan Liu  1/31/97
  17 // History:
  18 // 06/04/97   helena         Updated setImplementation as per feedback from 5/21 drop.
  19 // 04/07/1999  srl               refocused as a thin wrapper
  20 //
  21 //----------------------------------------------------------------------------
  22 #ifndef MUTEX_H
  23 #define MUTEX_H
  24
  25 #include "unicode/utypes.h"
  26 #include "unicode/uobject.h"
  27 #include "umutex.h"
  28
  29 U_NAMESPACE_BEGIN
  30
  31 //----------------------------------------------------------------------------
  32 // Code within that accesses shared static or global data should
  33 // should instantiate a Mutex object while doing so. You should make your own
  34 // private mutex where possible.
  35
  36 // For example:
  37 //
  38 // UMutex myMutex;
  39 //
  40 // void Function(int arg1, int arg2)
  41 // {
  42 //    static Object* foo;     // Shared read-write object
  43 //    Mutex mutex(&myMutex);  // or no args for the global lock
  44 //    foo->Method();
  45 //    // When 'mutex' goes out of scope and gets destroyed here, the lock is released
  46 // }
  47 //
  48 // Note:  Do NOT use the form 'Mutex mutex();' as that merely forward-declares a function
  49 //        returning a Mutex. This is a common mistake which silently slips through the
  50 //        compiler!!
  51 //
  52
  53 class U_COMMON_API Mutex : public UMemory {
  54 public:
  55   inline Mutex(UMutex *mutex = NULL);
  56   inline ~Mutex();
  57
  58 private:
  59   UMutex   *fMutex;
  60
  61   Mutex(const Mutex &other); // forbid copying of this class
  62   Mutex &operator=(const Mutex &other); // forbid copying of this class
  63 };
  64
  65 inline Mutex::Mutex(UMutex *mutex)
  66   : fMutex(mutex)
  67 {
  68   umtx_lock(fMutex);
  69 }
  70
  71 inline Mutex::~Mutex()
  72 {
  73   umtx_unlock(fMutex);
  74 }
  75
  76 U_NAMESPACE_END
  77
  78 #endif //_MUTEX_
  79 //eof